Electronic and optical properties of AlN nanosheet: An ab initio study

The electronic and the linear optical properties of AlN nanosheet are investigated through the density functional theory. The dielectric tensors are derived within the random phase approximation (RPA). Specifically, the dielectric function, absorption coefficient, optical conductivity, extinction index, reflectivity and their fraction index of the AlN nanosheet are calculated for both parallel and perpendicular electric field polarizations. The results show that the optical spectra are isotropic along these two polarizations. Optical conductivity in both the parallel and the perpendicular electric field starts with a gap which confirms that the AlN nanosheet has semiconductor property.